For fifteen tense minutes on Thursday afternoon, United Airlines' fare booking engine was operating at full steam. Someone, likely a Flyertalk user, noticed that fares between Washington DC and Minneapolis were pricing at $10 and posted his finding onto the forum. Attention grew rapidly, with over 100 replies in just an hour, and the news spread to Twitter.

The glitch in the system appeared to offer $0 fares plus $5 in tax for many domestic flights, and was apparently caused by human error. Some forum readers reported finding $10 flights between Washington DC and Hawaii, while others scooped up over a dozen tickets to destinations all over the country.

And then, just as quickly as the airfares showed up, United's reservation system slammed to a halt, reporting "United.com is currently undergoing maintenance Flight search and booking are unavailable for all flights, including MileagePlus award travel. We are working to restore these as quickly as possible."

As to whether the airline will honor the bookings, the consensus is unclear. Past errors in pricing have brought investigations from the Department of Justice after the airline rescinded the tickets, while other airlines have been more successful in canceling mistake fares. While some argue that the airline advertised and sold the fares in good faith, others argue that a clearly erroneous fare shouldn't need to be honored.

It is more than likely that United will have to weigh the costs and benefits of canceling a swath of tickets and incurring the consumer wrath versus honoring them and taking the financial hit. Calls to United for comment after the booking engine was closed were not immediately returned.

Update: Mary Clark from United Airlines reached out with the following statement.

One of our filings today contained an error which resulted in certain fares displaying as zero. We have corrected this error.

A separate spokesman also reached out to point out that the fare was caused by human error.

Edit: An earlier version of this story listed Houston as the departing city to Minneapolis. That has been updated to Washington DC.